How to Repair a Sprinkler Valve

hands repairing sprinkler in grass

Your lawn watering system is only effective if every sprinkler valve is working properly. Sprinkler valves can suffer damage when you run over the sprinkler heads with your mower or lash them with the weed slicer. Here are tips on repairing sprinkler valves to prevent future problems.

Step 1 - Check the Sprinkler Heads for Damage

If the sprinkler head is clogged, dented or scraped, the valve inside it may be out of commission as well.

Step 2 - Turn Off the Sprinkler System and Water Supply

Shut off the sprinkler system controller before beginning any repair so it can not initiate a watering program. Before disassembling the sprinkler head to get at the valve, turn off the water supply. You can be injured if you try to release the valve while it is under water pressure.

Step 3 - Remove the Solenoid

Release the sprinkler valve solenoid—a thin cylinder with a wire protruding from each end—from the sprinkler head by unscrewing it in a clockwise direction. A plunger is located near the solenoid. Check that the plunger can release and retract freely.

Step 4 - Unscrew the Top of the Sprinkler Valve Housing

The housing will have either a bonnet top fastened down with two or more screws or a jar-type top with grooves that must be twisted to release. Open the top to remove the flexible diaphragm and spring in the sprinkler valve.

The diaphragm may be in the body of the valve housing or wedged into the bonnet or jar top. Check how the diaphragm and spring are situated so you can reassemble them correctly.

Step 5 - Examine the Diaphragm and Spring

Check for any tears, rips, or holes in the diaphragm, and look over the spring to see if it has no nicks, scrapes, warped sections, or dents. Squeeze the spring gently between your fingers and release it: it should release the tension instantly.

Rinse off the diaphragm with fresh water to remove any particles or debris. If either the diaphragm or spring is damaged, replace them with new parts.

Step 6 - Inspect and Clean

Clean the rest of the valve housing, removing pebbles, mud, sand, and any leaf or grass residue. Look inside the bonnet or jar top to check for any nicks or grooves. Check the 2 ports in the valve housing, and remove any blockages with a piece of thin wire.

Step 7 - Replace any Damaged Parts and Reassemble the Sprinkler Valve

Once you find and replace any damaged parts, put the sprinkler valve back together as it was. Carefully tighten the screws in the bonnet or the lip of the jar top, and reinsert the valve mechanism firmly into the sprinkler head.

Step 8 - Restore the Water Supply and Test Your Repair

Reopen the water supply to the sprinkler system, reactivate the controller and test the sprinkler valve repair. Repeat this process if you find any other nonfunctional sprinkler heads in your sprinkler system.